The conduct of business today requires the generating, handling, and processing of vast quantities of documents. The information on many of these documents must be read and understood, and then processed for further action depending upon the information on the document. By way of example, a check may have to be read and processed further to properly debit the account of the payor. Or, the address on a mailing envelope, including a zip code, may have to be read before the envelope is forwarded to its proper bin for distribution. Various automatic reading apparatus have been developed, including bar code reading equipment, magnetic-ink character reading devices, optical scanners, and the like, to increase the speed at which documents are processed. As the newly developed procedures related to reading and handling of documents have decreased the time necessary to interpret documents, the speed at which such documents can be passed through document handling apparatus has increased. Document handling apparatus has been developed to automatically and rapidly transmit documents, one at a time, from a feeding station, through a transport station, and to a further processing station, for example, the latter comprising a document indicia reading station.
Some presently available document handling apparatus of the type referred to herein utilize document feed systems which may include intermittently driven roller devices at the end of a spring loaded horizontally disposed edgewise stack of documents, for example, to feed documents, preferably one at a time, from the end of the stack to a transport station having a separating mechanism which sequentially delivers individual documents to the next work or processing station. Since many of the documents in the stack, such as checks, envelopes, or the like, may be of different sizes or paper quality, and have different effective coefficients of friction between adjacent pairs of documents, it is often difficult to ensure the feeding and advancement of one document at a time from the stack.
After a document has been typically advanced laterally from the end of a stack of documents, it is advanced between a pair, or possibly multiple pairs, of nip rollers, which nip rollers are disposed downstream in the direction of feed once the document has been removed from the stack. Certain nip roller assemblies currently in use provide two functions. First, some nip roller assemblies merely advance the document forward to its next work station, while in some other instances they accelerate the speed of document travel compared to the speed of original removal from the stack of documents at the feed station. Second, certain nip rollers have been designed to perform a separation function by preventing the feed of more than one document at a time from the stack. For example, in addition to forwardly driven nip rollers to engage and advance a properly fed single document, an additional reverse driven roller may be provided to engage one side of a group of multiple documents improperly passing through the nip rollers for the purpose of driving none but the sequentially first or end-most document from the stack to the next station. The other, improperly fed, multiple documents contacted by the reversely driven roller are driven backwards, or their forward motion is halted, depending upon the friction generated between the documents.
Presently available document separation mechanisms of the type described do not provide intelligent means at the nip of the document advancing rollers to sense the condition of the feeding process, namely whether one or multiple documents are being fed through the document separation system, and to control further action of the document feed system responsive to conditions at the point of juncture of the nip rollers. Multiple document feed sensing systems presently in use normally detect a multiple feed condition downstream of the nip rollers, where it may be too late to initiate a control signal to activate the appropriate corrective servo motors or other control elements in time to prevent multiple documents from advancing through the entire system.
Therefore, a primary object of the present invention is to provide a document feed and separation mechanism which efficiently feeds documents one at a time from an initial stack of documents and advances individual documents to a further work or processing station, without any of the shortcomings of currently available devices noted above.
Yet another object of the present invention is to provide a document advancing roller assembly for an intelligent document separation system which prevents the advancement of more than one document at a time to a transport station, using a single roller element forming part of a nip roller assembly which automatically rotates in a forward mode, in a reverse mode, or is stopped depending upon certain conditions of the document feeding operation.
An additional object of a first embodiment of the present invention is to provide a nip roller assembly for engaging and advancing a moving document after the document has been removed from a stack of documents, which nip roller assembly includes a selectively rotatable drive roller unit and a back-up roller unit, the latter being selectively driven by a single rotating shaft, such that the nip roller assembly is capable of driving a single document forward; of reversing the movement of all but one document when a plurality of documents are inadvertently fed into the nip roller assembly; of advancing documents one at a time when a plurality of documents are inadvertently lodged up against the back-up roller, but not fed into the nip between the drive roller unit and the back-up roller unit; and of initiating a document feed sequence when there are no documents between the drive roller unit and the back-up roller unit.
An object of another embodiment of the present invention is to provide a nip roller assembly for engaging and advancing a moving document after the document has been removed from a stack of documents, which nip roller assembly includes one roller which is selectively driven by a single rotating shaft and is capable of driving a single document forward, or, of halting the forward progress of the second of two advancing documents, and/or of reversing the forward progress of any additional documents which may have been inadvertently removed from the stack.
Still another object of the present invention is to provide a unique document separation system including a drive shaft assembly for a drive roller which selectively drives or halts the drive roller automatically in response to the presence or absence of a single or multiple documents disposed between the drive roller and an adjacent back-up roller.
A further object of the present invention is to provide a nip roller assembly for engaging a moving document after the document has been removed from a stack of documents, which nip roller assembly includes a back-up roller drive shaft constantly driven in a single direction, and a back-up roller element capable of being operatively connected to said constantly rotating drive shaft whereby the nip roller assembly's back-up roller element can rotate in either a forward or reverse direction, or be stopped, relative to movement of a document advancing from a feed station, depending upon the number of documents being fed simultaneously from the feed station to the nip roller assembly.
Another object of the present invention is to provide a sensing device responsive to document feed conditions at the point where the document separation system of the present invention initially engages (1) a document properly fed, or (2) multiple documents improperly fed, from a document feeding station. A further object is to transmit the signal created in the sensing device to a controller unit to control further operation of the document feed and document separation systems depending upon whether documents have been properly or improperly advanced from the stack of documents.